Wedge for dental matrix bands

ABSTRACT

A wedge structure adapted to be used in association with dental matrix bands of the type utilized when inserting filling material in tooth cavities. The wedge structure is adapted to be inserted between a tooth carrying a band and an adjacent tooth whereby the wedge will serve to tightly hold the band against the tooth. The wedge preferably defines a triangular cross section and a serrated fin appendage on the stem whereby the wedge is particularly suited for insertion at the base of adjacent teeth in the area where undesirable movement of filling material is most prevalent.

United States Patent 1191 Eames 1 1 WEDGE FOR DENTAL MATRIX BANDS [76]Inventor: Wilmer B. Eames, 3898 Sable Dr.,

Stone Mountain, Ga. 30083 [22] Filed: June 18, 1973 [21] Appl. No.:370,778

[52] US. Cl. 32/63 [51] Int. Cl Afilg 5/12 [58] Field of Search 32/64,63

[56] References Cited UNITED STATES PATENTS 1,806,718 5/1931 Spanier32/64 2,150.005 3/1939 McNinch 32/64 2,782,503 2/1957 Thompson 1 32/632,891,313 6/1959 Crowley 1 1 32/63 3.193.094 7/1965 Schulsted 32/64 [11]3,815,243 1451 June 11, 1974 Primary ExaminerRobert Peshock Attorney,Agent, or FirmMcDougall, Hersh & Scott [57] ABSTRACT A wedge structureadapted to be used in association with dental matrix bands of the typeutilized when inserting filling material in tooth cavities. The wedgestructure is adapted to be inserted between a tooth carrying a band andan adjacent tooth whereby the wedge will serve to tightly hold the bandagainst the tooth. The wedge preferably defines a triangular crosssection and a serrated fin appendage on the stem whereby the wedge isparticularly suited for insertion at the base of adjacent teeth in thearea where undesirable movement of filling material is most prevalent.

1 Claim, 7 Drawing Figures WEDGE FOR DENTAL MATRIX BANDS This inventionrelates to the filling of teeth and, in particular, the inventionconcerns means for securely positioning a dental matrix band around atooth during the insertion of filling material into a tooth cavity.

Dental matrix bands, for example, of the type disclosed in copendingapplication Ser. No. 334,004, filed Feb. 20. 1973 and entitledPre-Formed Dental Matrix Band" are widely used during the filling ofteeth. These bands are typically formed from a flexible metal strip, forexample a stainless steel strip having reasonably high tensile strengthand good ductility. By utilizing a suitable retainer, the bands can besecured relative to a tooth with the band surfaces conforming to theshape of the tooth. Under these conditions, a cavity which has beenprepared by the dentist can be filled, and the filling material isprevented by the band from moving outwardly beyond the cavity area.

Problems develop with prior matrix bands from the standpoint ofachieving proper contour of the tooth surfaces after the cavity has beenfilled. Thus, it is desirable .to achieve anatural shape for the toothwith the filling in place, and the band position during filling is notalways suitable for achieving this purpose. This leads to fillings ofinferior quality which may require additional work on the part of thedentist, and discomfort for the patient.

Contact of excess filling material with the gingiva can lead to problemsfor the' patient, and the matrix bands are preferably designed so thatthey will prevent passage of the filling material beyond the gingivalborder. With prior band designs, this cannot be readily achieved and,therefore, additional problems result for the dentist and patient.

In the aforementioned copending application, there is described a dentalmatrix band structure which is particularly suitable for overcomingproblems of the type referred to. The matrix band is specificallydesigned so that a desirable shape for a tooth filling can be achieved,and so that any spreading of filling mate rial beyond the desired areacan be minimized.

It is a general object of this invention to provide further improvementsin the use of dental matrix bands, particularly from the standpoint ofsecuring the bands in position during a cavity-filling operation.

It is a still further object of this invention to provide a wedgestructure for use in association with a dental matrix band construction,the wedge structure being uniquely suitable for holding a band in placeduring use.

These and other objects of this invention will appear hereinafter andfor purposes of illustration but not of limitation, specific embodimentsof the invention are shown in the accompanying drawings in which:

FIG. 1 is a perspective view of a wedge structure characterized by thefeatures of the invention;

FIG. 2 is a cross-sectional view of the wedge structure taken adjacentthe head portion thereof;

FIG. 3 is a cross-sectional view of the wedge structure taken closer tothe tip portion thereof;

FIG. 4 is a side elevational view of the wedge structure;

FIG. 5 is a fragmentary side elevational view illustrating the wedgestructure in association with a dental matrix band located around atooth;

FIG. 6 is a plan view, partly in section, illustrating a pair of wedgestructures positioned between adjacent teeth for holding a matrix bandin position relative to one tooth; and,

FIG. 7 is a plan view illustrating association of wedge structures withtwo separate teeth.

This invention is generally concerned with the application of dentalmatrix bands and with the securing of the bands in place duringinsertion of filling material in a cavity of the tooth which the bandsurrounds. The specific improvement of the invention involves a wedgestructure which is adapted to be inserted between the tooth carrying theband and an adjacent tooth whereby the band is held tightly in positionagainst the tooth. The wedge is designed so that it will convenientlyfit in the area of the tooth base whereby the wedge is particularlyeffective for purposes of preventing any passage of filling materialbeyond the gingival border.

The wedge structure contemplated by this invention is preferably formedof a soft plastic material so that the wedge will be deformed whenpressed between teeth thereby insuring a good hold of the wedge relativeto the teeth. Furthermore, serrations are preferably located on a stemportion defined by the wedge to also increase the holding capability. Anenlarged head is provided for the wedge to facilitate insertion of thewedge between teeth. In order to accommodate the wedge to the spacebetween teeth, it has been found that a triangular cross section for thewedge stem will provide the most efficient insertion capability.

A preferred form of the invention is illustrated in the accompanyingdrawings wherein the particular wedge structure is best shown in FIGS. 1through 4. Specifically, the wedge 10 illustrated includes a taperedstem portion 12 and an enlarged head portion 14. As best shown in FIGS.2 and 3, the stem portion 12 is of triangular cross section.

Serrations 16 are defined by fins protruding from the stem at least inthe central area thereof. As illustrated, these fins extend outwardly onboth sides of a base wall 17 of the triangular stem. The pointed end 18of the stem is provided to facilitate entry of the wedge between teeth.The serrated fins 16 then serve to hold the wedge in place between theteeth after insertion and during a filling operation.

The enlarged end 14 defines an annular recess 20 which facilitatesplacement and removal of the wedge. That is, the head can be grippedmore easily with the fingers or with small forceps by providing thisrecess. The large surface area of the head also facilitates insertion ofthe wedge between teeth; and this insertion can be accomplished bypressing inwardly on the head with a finger or through the use of anappropriate tool.

FIGS. 5 through 7 illustrate association of the wedges with a bandlocated in surrounding relationship relative to a tooth. In eachinstance, the tooth defines a cavity having filling material 22' locatedwithin the cavity. In accordance with dental practice, this fillingmaterial is located in the cavity after a matrix band has been locatedin position. As explained in the aforementioned application, anyappropriate tool may be utilized for gripping the opposite ends of aband once the band is located in surrounding relationship relative to atooth.

The wedges 10 are shown inserted in the area of base portions ofadjacent teeth. In particular, the wedges'are introduced so that oneside wall 19 of the triangular surface of a wedge presses against amatrix band 24 while the opposite surface side wall 19 presses againstthe adjacent tooth. The base 17 of the wedge then rests on the gingivaltissues and for this reason, the triangular configuration of the wedgerepresents an important aspect of its structure. Thus. thisconfiguration provides an ideal arrangement for tightly holding the bandmaterial against the tooth being filled so that any migration of fillingmaterial toward the gingival border is substantially eliminated, Thefins 16 hold the wedge securely in position by pressing against the bandand tooth.

As illustrated in FIGS. 6 and 7, a pair of wedges may be associated withone band by inserting the wedges in opposite directions. Thisarrangement is particularly useful where the filling material might tendto migrate on both sides of a tooth. The wedge may be formed from anysuitable plastic material, preferably any nontoxic thermoplastic resinsuch as a polyvinyl chloride resin. By utilizing a soft plasticmaterial, a more secure fit of a wedge relative to a band is achieved.Furthermore, the plastic wedges can be produced on a highly efficientbasis so that the inexpensive wedges can be disposed of after each usethereby providing an ideal arrangement from a sanitation standpoint.

It will be understood that various changes and modifications may be madein the above described construction which provide the characteristics ofthe invention without departing from the spirit thereof particularly asdefined in the following claims.

That which is claimed is:

1. In the application of a dental matrix band for use in the filling ofa tooth wherein the band is positioned around the tooth during insertionof filling material, the improvement in means for holding the bandtightly in position around the tooth comprising at least one wedgeinserted between said tooth and an adjacent tooth, said wedge beingformed of a soft plastic mate- 4 rial whereby the wedge is deformed whenpressed between teeth, said wedge comprising an elongated tapered stemportion, said stem portion having a triangular cross section including abase spanning the gap between the teeth and positioned in contact withthe gingival, said base including outwardly extending serrated finsformed along both side edges thereof assisting in holding the wedge inposition, the top edge of the stem comprising a substantially straightedge and wherein the base tapers sharply toward the top edge adjacentthe end of the wedge, and an enlarged head portion for facilitatinginsertion of the wedge between the teeth, the wedge thereby holding theband tightly around the tooth, said head portion including an annularrecess defined at approximately the midsection of the head portion forfacilitating gripping of the head.

1. In the application of a dental matrix band for use in the filling ofa tooth wherein the band is positioned around the tooth during insertionof filling material, the improvement in means for holding the bandtightly in position around the tooth comprising at least one wedgeinserted between said tooth and an adjacent tooth, said wedge beingformed of a soft plastic material whereby the wedge is deformed whenpressed between teeth, said wedge comprising an elongated tapered stemportion, said stem portion having a triangular cross section including abase spanning the gap between the teeth and positioned in contact withthe gingival, said base including outwardly extending serrated finsformed along both side edges thereof assisting in holding the wedge inposition, the top edge of the stem comprising a substantially straightedge and wherein the base tapers sharply toward the top edge adjacentthe end of the wedge, and an enlarged head portion for facilitatinginsertion of the wedge between the teeth, the wedge thereby holding theband tightly around the tooth, said head portion including an annularrecess defined at approximately the midsection of the head portion forfacilitating gripping of the head.